Project restructuring...

Preparing for the day one the import objects are different than the
export / public objects.
Fix namespaces after restructuring
More reorganization
Make all import classes internal.
Enable NuGet and include Json.NET.
Add new test project

Turn all Import classes back to public so that the XmlSerializer works
again.
Start adding public facing classes that will be a more simplified view
of the Import classes.
Add reference to Json.NET via NuGet.